With oil now approaching $120 a barrel the country is now alert to the fact that heating a home will be one of the prime considerations. Home builders are taking this in to account as well and are implementing many changes in construction techniques to produce highly-efficient homes. There are three main areas where a contractor can build-in energy efficiency so that down the road the homeowner doesn't have to renovate to improve the heat retention.

1. Insulation

Fiberglass

The standard exterior wall stud in a wood-construction home is now 6 inch, which is actually 5 1/2 inches. This means that fiberglass batt insulation (at R-3 per inch) can be used to fill this space and should not be compressed to fit. This negates the optimum R-value of the insulation. At this thickness the wall has an R-value of 17.5 and the wood stud is even at 1 inch = R-1 which is 5.5. In the ceiling the R-value should be 40 + which means a minimum of 13.5 inches. Basement walls should be framed and insulated to the floor. If not perfectly installed air channeling can occur and find its way to plugs and outlets and into the home.

Foam

A low-pressure formula is sprayed on and leveled off before the drywall goes on or it can be applied after the drywall is installed and before the taping is done. This great product fills all the cavities and has a better R-value (7 per inch) than fiberglass but is 3 times more expansive.

Cellulose

Cellulose is shredded newspaper that is blown into attics in a loose pile. This has the same R-value as fiberglass. A wet version is blown at the inside of the exterior wall between the studs. The paper mache-like paste sticks to the wall and is troweled flat so that drywallers can have a smooth surface on which to work. Mold inhibitors and fire retarding chemicals make it safe against pests and fires. Like foam, this insulation gets into all the spaces and seals the wall.

Insulated Concrete Forms

Insulated Concrete Forms, of ICF's, become the forms for pouring the concrete walls and stay in place after the cement sets. The preformed foam comes in either interlocking blocks or separate panels with plastic webs that hold reinforcing steel rods. ICF's not only provide both insulation and sound barrier and also a plumb platform for interior drywall and, on the outside, stucco, siding, or brick. On the whole the building system is 10% more than wood-frame construction but it goes right down to the foundation forming and insulating basement areas. The R-value for ICF walls is between R-18 to 20 and there is no threat of air channeling.

Structural Insulation Panels

Commonly called SIPs, these panels are sheets of oriented strand board (OSB) sandwiching a thick extruded polystyrene sheet. SIPs are so strong they are not only replace framed walls but take the place of trusses for the roof, as well. In effect, unlike ICF's which need wooden roof trusses, you can build the entire exterior of a home with these panels. In addition, like ICF, the walls are sealed allowing no air flow. A 6.5 inch wall, which is similar to a 2 X 6 wood-frame wall with insulation, vapor seal and outer shell, is between R-25 and R-30.

2. Windows

Windows are the biggest energy leak in the home. In fact there are minute air currents within sealed glass that convey heat to the outside. This heat loss is reduced with the use of low-E [low-emissivity] shields for the glass that reflects heat inward during the winter and deflects radiant heat during the summer. A third layer of glass greatly cuts down on heat transfer to the outside. The argon gas is heavy and resists the air channels. Many contractors offer four-paned windows featured two plastic sheets in the inside. Plastic cuts down the transfer of heat outward and makes the windows much lighter.

The placement of windows is also important for long-term energy savings. Never put large windows on the western side of the home because, at certain times of the year (usually the hottest), the sun will be almost horizontal and your air conditioner will have to work overtime to keep the house cool. Conversely, in the winter, passive solar energy through a well-placed window can help your heat bill.

Windows and doors must be hung properly to prevent air leakage. Many sloppy jobs have led to a serious waste of energy. This is why many contractors take extra case in sealing around these openings before the moldings go on.

3. Vapor Barrier

In wood-frame homes vapor barrier is put between the insulation and the drywall to prevent moisture in the home from compromising the insulation. Once the insulation is wet mold and insects can infest the wall making the home unsafe. Vapor barrier also acts as a regulator for relative humidity in the home allowing the air exchanger to work more efficiently. Properly sealed around electrical outlets, doors and windows and light fixtures vapor barrier is the last defense against air escaping in through the exterior.

4. House Wrap

Like a good ski jacket, which repels rain and wet snow while allowing the wearer's perspiration to escape, house wrap is like a one-way door. Basically, it is a matt of spun polyethylene which has the unique property of preventing moisture from entering a home but allowing moisture inside the walls to escape. This lessens the possibility of mold and soggy insulation. It also blocks wind which can come in through the siding.

Whatever method you may chose to build your home keep in mind that energy costs never go lower, just higher. So, you have to build an energy-efficient home for the future. For infomration on how you can build an enegy-efficient home contact Renovation Experts.